1. Field of the Invention
This invention relates generally to shears for cutting and thinning hair.
2. Prior Art
A pair of cutting shears for cutting hair typically includes a pair of blades with continuous if cutting edges for cutting all the hair positioned there between. In some hair styling techniques, the hair is thinned or reduced in bulk with a pair of thinning shears, which typically includes a blade with a continuous cutting edge, and another blade with alternating teeth and gaps in its cutting edge. The teeth cut the hair when the blades are closed, but the gaps leave some hair uncut, so that only about half the hair is cut in each stroke. A pair of thinning shears is shown in U.S. Pat. No. 5,107,591 to Sato. The thinning operation is often performed by hairdressers, but typical cutting shears and thinning shears are separate tools, so that hairdressers must frequently switch shears.
Various patents show cutting shears combined with other tools. U.S. Pat. No. 312,292 to Pribyl shows a pair of shears with a notched wheel pivotally attached to one of the finger rings for marking things. U.S. Pat. No. 422,670 to Wallace shows a pair of shears with a screwdriver blade attached to one of the finger rings, and a claw attached to the other finger ring for removing tacks. U.S. Pat. No. 574,178 to Stebbins shows a pair of shears with a screwdriver blade attached to one of the finger rings, and a can opener attached to the other finger ring. None of these shears can thin hair. U.S. Pat. No. 3,831,277 to Nagata shows a pair of shears with a pair of cutting blades mounted in parallel to a pair of thinning blades. A shifting piece is moved to lock or release the cutting blades relative to the thinning blades, so that the shears can either cut or thin, or cut and thin simultaneously. However, the shifting operation is confusing, so hair can easily be unintentionally cut or thinned if the blades are in the wrong position. The four blades mounted together substantially increase the thickness and weight of the tool, so that it is awkward to use. Their substantially different feel and operation make them difficult to learn, so that they are unlikely to be adopted by professional hairdressers, who cannot afford to be slowed down by an unfamiliar tool.